Common Juniper
Juniperus communis | Cupressaceae
Submission: Cecilia McQuaid and Noah Smith
Identification:
Leaves – Awl-shaped; about ¼-¾inch long; glaucous above; usually ternate, occur in whorls of 3, sharp-pointed, and persistent; upper surface is concave, marked with a broad, white line; underside is dark green (usually appears as uppermost side because of bending of the twigs); similar to Eastern Red Cedar
Twigs and Buds – tend to be yellowish or green when young but turn brown and harden when they are older; Male strobili are sessile or stalked, and female strobili are made up of green, ovate, or acuminate scales
Fruit – covered with a thin bloom and pea-sized; remains on the tree in winter and has a strong resinous taste; dioecious, male and female flowers are produced on different trees (as with other junipers). Berries used to flavor gin (gin means juniper in old French)
Cones – ⅓ inch long; subglobose; dark blue/purple, glaucous, berry-like
Bark – Grayish-brown; occurs in thin, longitudinal, shredded layers
Silvics:
The Common Juniper is a native and prevalent shrub across the United States. Its height commonly remains between 2 to 4 meters, with maximum heights recorded up to 7 meters tall. They can thrive on almost any soil type with good water drainage, and are characteristic of meadows, open fields, shallow rocky soil, rocky cliffs, and steep ledges. Common Junipers grow best with full sunlight and do not thrive in heavily shaded areas. Because of its great adaptability, Common Junipers occur naturally across most of the World and are frequently planted as ornamentals. The International Union for Conservation of Nature lists Common Juniper as a species of least concern due to its adaptability, versatility, and large, widespread population. The Common Juniper is the most widespread conifer species around the world and has very limited identified threats.
Natural History:
Indigenous people in North America used Common Juniper for various health ailments. Native Americans of the Pacific Northwest used tonics made from branches to treat colds, flu, arthritis, muscle aches, and kidney problems. Other indigenous peoples around the world have used Common Juniper for various organ problems, including, stomach ailments, respiratory problems, and rheumatism. The volatile oil in the Common Juniper has been used to increase kidney function and also as a meat preservative. Its berries are also an essential component in the flavoring of Gin.
References:
IUCN 2023. The IUCN Red List of Threatened Species. Version 2022-2.
Maine Forest Service. 2008. Forest Trees of Maine. Centennial Edition. Maine: Maine
Department of Agriculture, Conservation & Forestry
Shane, J. 2008. Dendrology Handbook, University of Vermont, Unpublished.
Tirmenstein, D. 1999. Juniperus communis. In: Fire Effects Information System, [Online]. U.S.
Department of Agriculture, Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory (Producer).